diff --git a/components/layout/block.rs b/components/layout/block.rs
index b84e0da50f7..ba17b417963 100644
--- a/components/layout/block.rs
+++ b/components/layout/block.rs
@@ -1448,6 +1448,10 @@ impl Flow for BlockFlow {
         self.fragment.style().get_box().clear
     }
 
+    fn float_kind(&self) -> float::T {
+        self.fragment.style().get_box().float
+    }
+
     /// Pass 1 of reflow: computes minimum and preferred inline-sizes.
     ///
     /// Recursively (bottom-up) determine the flow's minimum and preferred inline-sizes. When called on
@@ -1473,25 +1477,45 @@ impl Flow for BlockFlow {
 
         // Find the maximum inline-size from children.
         let mut intrinsic_inline_sizes = IntrinsicISizes::new();
+        let mut left_float_width = Au(0);
+        let mut right_float_width = Au(0);
         for child_ctx in self.base.child_iter() {
             assert!(child_ctx.is_block_flow() ||
                     child_ctx.is_inline_flow() ||
                     child_ctx.is_table_kind());
 
+            let float_kind = child_ctx.float_kind();
             let child_base = flow::mut_base(child_ctx);
 
             if !fixed_width {
                 intrinsic_inline_sizes.minimum_inline_size =
                     geometry::max(intrinsic_inline_sizes.minimum_inline_size,
                                   child_base.intrinsic_inline_sizes.total_minimum_inline_size());
-                intrinsic_inline_sizes.preferred_inline_size =
-                    geometry::max(intrinsic_inline_sizes.preferred_inline_size,
+
+                match float_kind {
+                    float::none => {
+                        intrinsic_inline_sizes.preferred_inline_size =
+                            geometry::max(intrinsic_inline_sizes.preferred_inline_size,
                                   child_base.intrinsic_inline_sizes.total_preferred_inline_size());
+                    }
+                    float::left => {
+                        left_float_width = left_float_width +
+                                    child_base.intrinsic_inline_sizes.total_preferred_inline_size();
+                    }
+                    float::right => {
+                        right_float_width = right_float_width +
+                                    child_base.intrinsic_inline_sizes.total_preferred_inline_size();
+                    }
+                }
             }
 
             flags.union_floated_descendants_flags(child_base.flags);
         }
 
+        intrinsic_inline_sizes.preferred_inline_size =
+            geometry::max(intrinsic_inline_sizes.preferred_inline_size,
+                          left_float_width + right_float_width);
+
         let fragment_intrinsic_inline_sizes = self.fragment.intrinsic_inline_sizes();
         intrinsic_inline_sizes.minimum_inline_size = geometry::max(intrinsic_inline_sizes.minimum_inline_size,
                                                        fragment_intrinsic_inline_sizes.minimum_inline_size);
diff --git a/components/layout/flow.rs b/components/layout/flow.rs
index 2759ebbe74b..7a4c98a8361 100644
--- a/components/layout/flow.rs
+++ b/components/layout/flow.rs
@@ -61,7 +61,7 @@ use std::iter::Zip;
 use std::raw;
 use std::sync::atomics::{AtomicUint, Relaxed, SeqCst};
 use std::slice::MutItems;
-use style::computed_values::{clear, position, text_align};
+use style::computed_values::{clear, float, position, text_align};
 
 /// Virtual methods that make up a float context.
 ///
@@ -195,6 +195,10 @@ pub trait Flow: fmt::Show + ToString + Share {
         clear::none
     }
 
+    fn float_kind(&self) -> float::T {
+        float::none
+    }
+
     /// Returns true if this float is a block formatting context and false otherwise. The default
     /// implementation returns false.
     fn is_block_formatting_context(&self, _only_impactable_by_floats: bool) -> bool {
diff --git a/tests/ref/abs_float_pref_width_a.html b/tests/ref/abs_float_pref_width_a.html
new file mode 100644
index 00000000000..65714506722
--- /dev/null
+++ b/tests/ref/abs_float_pref_width_a.html
@@ -0,0 +1,30 @@
+<!DOCTYPE html>
+<html>
+    <head>
+    <style type="text/css">
+        @font-face {
+            font-family: 'ahem';
+            src: url(fonts/ahem/ahem.ttf);
+        }
+        body {
+            margin: 0;
+            font-family: 'ahem';
+            font-size: 100px;
+            color: green;
+        }
+        div {
+            position: absolute;
+            left: 100px;
+        }
+        span {
+            float: left;
+        }
+    </style>
+    </head>
+    <body>
+        <div>
+            <span>X</span>
+            <span>X</span>
+        </div>
+    </body>
+</html>
diff --git a/tests/ref/abs_float_pref_width_ref.html b/tests/ref/abs_float_pref_width_ref.html
new file mode 100644
index 00000000000..2b35cb62eb4
--- /dev/null
+++ b/tests/ref/abs_float_pref_width_ref.html
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<html>
+    <head>
+    <style type="text/css">
+        body {
+            margin: 0;
+        }
+        div {
+            position: absolute;
+            left: 100px;
+            width: 200px;
+            height: 100px;
+            background-color: green;
+        }
+    </style>
+    </head>
+    <body>
+        <div>
+        </div>
+    </body>
+</html>
diff --git a/tests/ref/basic.list b/tests/ref/basic.list
index 0ffafba5dca..b785ddbd4c1 100644
--- a/tests/ref/basic.list
+++ b/tests/ref/basic.list
@@ -110,3 +110,4 @@ flaky_gpu,flaky_linux == acid2_noscroll.html acid2_ref_broken.html
 == float_intrinsic_width_a.html float_intrinsic_width_ref.html
 == float_right_intrinsic_width_a.html float_right_intrinsic_width_ref.html
 == fixed_width_overrides_child_intrinsic_width_a.html fixed_width_overrides_child_intrinsic_width_ref.html
+== abs_float_pref_width_a.html abs_float_pref_width_ref.html